Cod sursa(job #186626)

Utilizator tvladTataranu Vlad tvlad Data 28 aprilie 2008 14:42:42
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 1.02 kb
#include <cstdio>
#include <vector>
#include <set>
using namespace std;

const int N = 50000;
const int INF = 0x3f3f3f3f;

int n,m;
vector< pair<int,int> > g[N];
int d[N];

class dist_cmp {
public:
	bool operator() ( int a, int b ) { return d[a] < d[b]; };
};

void dijkstra() {
	set<int, dist_cmp> s;
	d[0] = 0;
	for (int i = 1; i < n; ++i) d[i] = INF;
	for (s.insert(0); !s.empty(); s.erase(s.begin())) {
		for (vector< pair<int, int> >::iterator nx = g[*s.begin()].begin(); nx != g[*s.begin()].end(); ++nx) {
			int nd = d[*s.begin()] + nx->second;
			if (d[nx->first] > nd) {
				if (d[nx->first] != INF) s.erase(s.find(nx->first));
				d[nx->first] = nd;
				s.insert(nx->first);
			}
		}
	}
}

int main() {
	freopen("dijkstra.in","rt",stdin);
	freopen("dijkstra.out","wt",stdout);
	scanf("%d %d",&n,&m);
	for (int i = 0; i < m; ++i) {
		int a,b,c;
		scanf("%d %d %d",&a,&b,&c);
		--a; --b;
		g[a].push_back(make_pair(b,c));
	}
	dijkstra();
	for (int i = 1; i < n; ++i) printf("%d ",(d[i] == INF) ? 0 : d[i]);
	printf("\n");
	return 0;
}